Tinnitus refers to the perception of sound without an external source. It is often described as ringing, hissing, or whooshing. The exact cause is unknown but may involve damage to hair cells or abnormal neural activity in the auditory system. Around 40-50 million Americans experience chronic tinnitus, with around 2.5 million finding it debilitating. While the source is debated, it is thought to originate from changes in the brain rather than inner ear itself.

1. Tinnitus--Introduction AUD 733 Week 1

2. Tinnitus Definition: From the Latin tinniere (to ring) Refers to an auditory perception not produced by an external stimulus Commonly described as a ringing, roaring, hissing, or whooshing Ranging from high pitch to low pitch or even a noise-like sound (with no tonal quality)

3. Pronunciation Controversy Tin’-i-tis (stress on the first syllable and the middle “i” uses the short pronunciation) Tin-i’-tis (the middle “i” is long and the usual pronunciation of the suffix “itis” is used The controversy goes on

4. The Arguments The researchers and some individuals from the American Tinnitus Association (ATA) argue that “itis” should be pronounced with a long “i” , as described in numerous dictionaries The majority of other individuals use the short vowel sound for the middle “i” and may argue that “itis” with a long “i” suggest some sort of inflammation which is not accurate when referring to tinnitus

5. Suggestion Use whichever pronunciation you are comfortable with Explain briefly to your patients that they may here either pronunciation used and both are acceptable

6. What Tinnitus IS NOT Auditory hallucinations are not the same as tinnitus Auditory hallucinations may be psychological or may have a true neurologic foundation

7. More on What Tinnitus Is The exact pathophysiology of tinnitus is unknown Many Mechanisms have been sited as possibly producing tinnitus Outer hair cell decoupling from the tectorial membrane Hyperactivity of neural firing Hypoactivity of neural firing

8. Cont… Improper functioning of the olivocochlear bundle (efferent auditory pathways) resulting in a lack of normal inhibition

9. Basic Concepts on the Origin of Tinnitus It is the chronic perception of a sound that has no external source. The auditory sensation is continually generated by aberrant neuronal discharges in the auditory nervous system The brain erroneously interprets the signal as sound/s

10. Site of Origin The cochlea seems like a likely site because we know that damage to the cochlea from salicylates (aspirin), noise exposure, and other factors produce tinnitus But surgical severing of cranial nerve VIII with tinnitus remaining present points toward a central rather than peripheral origin

11. Postulated course of tinnitus (by Sweetow in Hearing Disorders , Ed. By Jerry Northern (1996)) “ An acute insult (or offending agent) leads to a chronic signal, which leads to a central modification, which leads to psychological enhancement, which leads to intractable tinnitus.”

12. Characterizations of Tinnitus As mentioned earlier, tinnitus can vary in pitch, loudness and tonal quality It may be constant, pulsed or intermittent It can arise suddenly or slowly It may be heard in the ear/s (tinnitus aurium) or in the head (tinnitus cranii)

13. Classifications Literature describes objective and subjective tinnitus Objective-is audible to an observer (using a stethoscope or by listening near the ear) Present in less than 5% of overall tinnitus cases Usually a cause can be determined and treated medically

14. Cont.. Objective Tinnitus Usually associated with vascular or muscular disorders Arteriovenous aneurysms, abnormally patent Eustachian tube/s, glomus jugulare tumors, palatal myoclonus, spasms or tics of the stapedius or tensor tympani muscle/s Often pulsatile and synchronous with the patient’s heartbeat

15. Subjective Tinnitus Audible only to the patient The most common, occurring in over 95% of tinnitus patients ( we will focus on subjective tinnitus for the rest of this course) Associated with practically every known otologic disorder Also related to a host of nonauditory pathologies See separate chart/page in course content for pathologies associated with subjective tinnitus CLICK HERE to view page now

16. Epidemiology View information from the Tinnitus Data Registry developed by the Oregon Health Sciences University (OHSU). It has been in existence since 1975 and has some data published at http://www. ohsu . edu / ohrc - otda / otda .html

17. Prevalence in the U.S. 40-50 million Americans experience chronic tinnitus Approx. 2.5 million are debilitated by the tinnitus

18. Other Facts About Tinnitus Approx 60% bilateral 30 %, unilateral 10% perceived in the head About three times more men than women seek treatment for tinnitus Why?

19. If a person has transient episodes of a tinnitus-like sound, it would not be considered chronic. If tinnitus occurs occasionally and only lasts a few minutes per episode, it would not be considered pathological.

20. What Makes Tinnitus a Problem? It is not known why tinnitus becomes or is a problem for some individuals and not for all who experience it. It is suggested, however, that individuals already predisposed to psychological disturbances are more likely to be negatively impacted by the existence of tinnitus.

21. Correlates No absolute correlation between the quality of the tinnitus and the etiology For example, low-frequency roaring tinnitus is often reported with Meniere’s disease but NOT always, and roaring tinnitus can occur with other conditions It is unknown if acoustical qualities correlate with the perceived severity of the problem For those who seek treatment, the loudness and pitch of the tones “matched” to the tinnitus do not predict the severity of the problem. We do not have data on those who are not bothered by their tinnitus and do not seek intervention.

22. Subjective Rating of Tinnitus Loudness On a scale of 1 to 10, 1 being the “softest sound imaginable” and 10 being the “loudest sound imaginable”, most of the subjects (70%) rate their tinnitus loudness between 4 and 8. About 20% rate it between 8 and 10, and 10% rate it below 4. Information From the Tinnitus Data Registry